These images are from the original published atlas:
Tenover, F. C., and J. V. Hirschmann. 1990. Interpretation of
Gram stains and other common microbiologic slide preparations.
The UpJohn Company, Kalamazoo, Mich. Permission granted
to the ASM MicrobeLibrary by Pfizer Inc.

This atlas was written to help clinicians,
microbiologists, and laboratory personnel identify organisms
in infected materials stained by techniques commonly used in
most clinical laboratories. Please refer to the atlas'
main page for more information and a guide to
all of the images.

Slide 1. Haemophilus influenzaeThese small,
pleomorphic Gram-Negative bacteria range in shape from round
(cocci) to short, thin rods (bacilli); hence the bacteria are
called “coccobacilli.” In specimens from patients with
pneumonia caused by Haemophilus influenzae, both
neutrophils and bacteria are usually plentiful. However, if
examination of the slide is not thorough, the coccobacilli may
be inconspicuous in the background of pink-staining mucus.
Other organisms, such as Eikenella corrodans or
Bacteroides species, are also pleomorphic Gram-Negative
coccobacilli; but they rarely cause pneumonia.

Slide 2. Haemophilus influenzaeMany coccobacilli
are present in the cytoplasm of the neutrophils, a common site
for Haemophilus influenzae in sputum stains. The
examiner should always look carefully for organisms in white
cells. (An alveolar macrophage is also present on this slide.)

Slide 3. Neisseria meningitidisNumerous
Gram-Negative diplococci are present, singly and in pairs. In
patients with pneumonia, the respiratory pathogens most likely
to have this appearance are Neisseria meningitidis or
Moraxella (Branhamella) catarrhalis which look alike.
Other Gram-Negative diplococci, such as commensal Neisseria
species or Veillonella species, are rarely the sole
or predominant organism in sputum smears of patients with
pneumonia.

Slide 4. Moraxella (Branhamella)
catarrhalisMoraxella catarrhalis can cause
pneumonia, especially in patients with alcoholism or chronic
obstructive lung disease. This slide shows many Gram-Negative
cocci, singly and in pairs. Like meningococci and
Haemophilus influenzae, Moraxella catarrhalis is often
visible within the cytoplasm of neutrophils.